1. Technical Field
This disclosure relates to an inkjet recording apparatus that is capable of preventing accumulation of disposal ink discharged for purposes other than recording.
2. Description of the Related Art
In an inkjet recording apparatus that records an image on a recording medium (e.g., paper) by discharging ink from a recording head, printing malfunction may occur when the apparatus is not used for a long time and the ink solidifies to clog up the ink nozzle of the recording head or when foreign particles or air bubbles clog up the ink nozzle, for example. Thus, when printing is not performed for a long time or when foreign particles or air bubbles clog up the ink nozzle, the inkjet recording apparatus is configured to perform idle discharge operations for discharging ink out of the ink nozzle and forcing the solidified ink, foreign particles, or air bubbles out of the ink nozzle together with the discharged ink to thereby clean and restore the ink nozzle.
FIGS. 1A and 1B are cross-sectional views of a maintenance/restoration device of an inkjet recording apparatus. The illustrated maintenance/restoration device includes a suction cap 202 for sealing the ink nozzle surface of an inkjet recording head 201, a tube 203 that is connected to the suction cap 202, a suction pump 204 that attracts the viscous ink, foreign particles, or air bubbles clogging the ink nozzle through the tube 203 with suction force, and a disposal liquid tank 205 that collects disposal liquid that is pumped out by the suction pump 205. When the disposal liquid is in liquid state, the disposal liquid may be evenly distributed within the disposal liquid tank 205 as is shown in FIG. 1A. However, when viscous ink or solidified ink is accumulated within the disposal liquid tank, the accumulated ink may not be evenly distributed and may be heaped up to block the disposal outlet of the tube 203 and hinder further disposal of liquid discharged from the recording head 201 even when the disposal liquid tank 205 is not full as is shown in FIG. 1B. In turn, the disposal liquid collected in the disposal liquid tank 205 may have to be frequently discarded so that operationality of the inkjet recording apparatus may be degraded, for example. It is noted that such a problem may be particularly prominent when ink with high viscosity such as pigment ink is used in a low humidity environment since such ink may be easily dried up. In turn, various techniques have been proposed for solving such a problem.
For example, Japanese Laid-Open Patent Publication No. 2001-293887 (D1) discloses arranging a rotating member for receiving disposal liquid discharged for purposes other than recording, securing some space at the upper side of the rotating member, and scraping off accumulated ink with the rotating member so that the accumulated ink may not reach above a predetermined height.
Japanese Laid-Open Patent Publication No. 2002-225313 (D2) discloses an inkjet recording apparatus that has a pigment disposal outlet and a dye disposal outlet arranged close to each other to cause the two types of disposal liquid to be mixed so that solidified pigment may be dissolved or the pigment disposal liquid may be prevented from solidifying.
Japanese Laid-Open Patent Publication No. 2006-031006 (D3) discloses a disposal toner collecting apparatus that includes a cleaning blade that scrapes and separates disposal toner remaining on the peripheral surface of a photoconductive medium, a disposal toner container that accommodates the disposal toner, a disposal toner path for carrying the separated disposal toner from the photoconductive medium to the disposal toner container, and a mixing blade that moves back and forth within the disposal toner path to prevent stagnation of the disposal toner.
Japanese Laid-Open Patent Publication No. 2005-144940 (D4) discloses the use of a sliding member that has plural sliding plates connected by connection ribs for removing disposal liquid that is accumulated at a sloped portion of an idle discharge liquid receiver onto which portion recording liquid is discharged, the sliding member being arranged to move back and forth in parallel directions with respect to the sloped surface portion without coming into contact with the sloped portion so that disposal liquid may be prevented from accumulating and growing at the sloped portion.
However, it is noted that the technique disclosed in D1 has a drawback in that ink may adhere to the rotating member that is used for scraping off the accumulated ink so that the space between the portion for receiving disposal liquid (ink) and the rotating member may gradually be reduced to prevent the accumulated ink from being effectively removed by the rotating member. Also, the technique disclosed in D2 has a drawback in that the pigment components cannot be completely dissolved so that accumulation of ink cannot be completely prevented. Also, it is noted that the technique disclosed in D3 is directed to mixing toner. Accordingly, toner may not adhere to the mixing plate, but in the case where ink is used, the ink may adhere to the mixing plate and cause malfunction of the mixing plate. Also, the technique disclosed in D4 has a drawback in that ink may adhere to the sliding member to enter the gaps created within the sliding member mechanism so that the sliding member may be prevented from operating properly when the ink solidifies within the gaps.